Push switches generating clicking feeling are used for various inputs. In the push switch in which a movable contact member is a metal dome, there is a case in which unintentional operation sound is generated when a pressing operation is stopped and the movable contact member returns to its initial state.
It is thought that releasing energy when the metal dome is reversed causes the movable contact member to collide with a fixed contact member or vibrations to be transmitted, etc., which in turn causes to the sound to be generated. If a movable contact member having a small operation load is used in order to reduce such an operation sound, the clicking feeling is changed, which is not preferable.
On the other hand, Patent Document 1 discloses a switch mechanism provided with a protrusion member formed of a rubber-like elastic body layer. FIG. 9 is a schematic sectional side view of the switch mechanism. As illustrated in FIG. 9, in this switch mechanism, a movable contact plate 113 is mounted on a switch substrate 110 on which a switch contact 111 is formed, a pressing plate 130 and a key top plate 140 are disposed thereon, and a case 170 is provided thereon to be covered. A switch contact 111 is provided at a position facing a key top 150. Above the switch contact 111, a movable contact plate 113 formed by forming a circular elastic metal plate into a dome shape is provided. As illustrated in FIG. 9, the pressing plate 130 is configured by attaching a protruding member 133 to a lower surface of a flat sheet-like flexible sheet 131. A protruding member 133 presses the movable contact plate 113 to invert the movable contact plate 113, which generates the clicking feeling, and the movable contact plate 113 comes into contact with the switch contact 111 to turn on the switch. The protrusion member 133 is formed by printing a rubber-like elastic layer on the lower surface of a flexible sheet 131.
When the movable contact plate 113 is pressed by the protrusion member 133 formed of the rubber-like elastic layer, sound and vibration hardly occur, and thus so-called sound elimination can be implemented.